In the early dawn hours on Tuesday, May 22, 2007, the Mardi Gras Shipwreck Project crew tossed off the lines holding TOISA VIGILANT to the dock in Fourchon, Louisiana and headed to sea. After a 7 hour transit to the shipwreck site, the survey and ROV crews began setting up the survey grid on the seafloor using the Triton ROV and five acoustic beacons.
The ROV began making trips to the seabed late Tuesday night to place the acoustic transponders on the bottom. The transponders will create an acoustic grid helping archaeologists create an accurate map of the wreck site. Before dawn the ROV pilots flew one pass over the shipwreck allowing archaeologists, ROV pilots and ship’s crew to view the site for the first time.
An hour after the ROV returned to the surface field crew created the first project mosaic allowing archaeologists to begin their work of interpreting the shipwreck. For the archaeological team the project has officially begun as they start the painstaking process of studying the relationship of each artifact on the seafloor to another.
Archaeologists study a shipwreck to understand who the people were that crewed it, what was important to them, and why the ship sank. To do this they need to know where each artifact is in relation to another artifact on the seafloor. Archaeologists used a high resolution camera mounted on the ROV to take digital images of the wreck site. These images are then stitched together to create a highly accurate digital mosaic of the shipwreck.
Once the images are stitched together they are geo-referenced, meaning that they are oriented on the site map with their correct latitude and longitude. Archaeologists will then use this digital mosaic to map and interpret the shipwreck.
While Texas A&M graduate students worked to create the mosaic, ROV pilots and archaeologists worked hand in hand throughout the night and early morning hours collecting wine bottles, and ceramics. Although high seas have prevented the crew from bringing the artifacts to the surface, the archaeological staff and ROV pilots are continuing to map the site, assign each artifact a unique artifact number, measure it using lasers, and label it on the map. While the archaeologists watch, the ROV pilot and copilot very delicately maneuver the ROV into position, and then using a suction tool pick up each artifact on the seafloor placing it into a numbered bin for transport to the ship’s deck.
Several days of choppy seas prevented the archaeological team from bringing artifacts from the Mardi Gras shipwreck to the surface until late Friday night. When the basket finally touched down on deck the project team was there to celebrate and examine these time worn objects. A tiny sand clock, a large stoneware jug, and numerous bottles remarkably survived the 4000-foot trip to the surface. For the first time in over two centuries these fragile objects were once more afloat in the Gulf of Mexico.
The conservation staff quickly took over care of the artifacts, photographing, measuring, and stabilizing each artifact in preparation for their long trip back to Texas A&M for conservation.
Late in the afternoon on Saturday the team recovered a pale blue glass bottle, embossed with the word LONDON. Quick research showed the bottle matched a previously identified mustard bottle from another archaeological site, allowing archaeologists their first opportunity to begin dating the site.
While the conservators worked through the weekend to document the artifacts, the ROV crew retooled the ROV for its next job – dredging around the compasses and telescope. With the dredge working, and new tools on the bottom the interdisciplinary team successfully brought numerous lead shot, a telescope, gun flints, and another small sand clock back to the surface for study early Tuesday morning.
In the days before June 1, 2007, archaeologists have continued mapping and excavating the site. The more delicate items have been recovered and brought to the surface including a salt shaker, buttons, a collection of plates, even pieces of a pocket watch.
Last night’s retrieval of the large artifact recovery box and the small artifacts inside it was met with awe and silence by the entire crew. These artifacts in many ways were more fragile than the first batch of bottles and ceramics. Once the artifacts were examined and placed into wet storage for the night, the crew began preparations for lifting the ship’s cannon.
The crew’s preparation and efforts met with success in the predawn hours on Friday when the cannon was rigged with two lifting straps, connected to the ship’s winch and hoisted to the surface. For the first time since the Mardi Gras vessel sank, its cannon was on the surface on a ship’s deck. The cannon’s original iron construction has now degraded to the point that only the biological and iron concretions on it’s exterior held it together for the lift. Even the biologist on the mission managed to examine some of the deepwater biological organisms that made their home on the cannon. The cannon now awaits transport and conservation at Texas A&M; as the crew prepares to lift the ship’s cast iron stove to the surface.
For the documentary filmmakers at Nautilus Productions illustrating archaeological activities on a shipwreck in 4000 feet of 33 degree water presents some problems. How do you show the "big picture" and understand the shipwreck when the only view you have of the wrecksite is from the ROV's camera? The only solution was 3D animation so the viewer can get a global view of the Mardi Gras Shipwreck on the bottom. This test animation represents nearly 2 months of work and a solid week of render time on a high speed computer.
